Rishi Sunak faces the most important vote of his premiership this evening when his ‘Safety of Rwanda’ bill has its second reading in the Commons. The bill seeks to finally get migrant flights off the ground by declaring Rwanda to be ‘safe’. If passed, the legislation will also mean that some international laws will have no effect, making a legal challenge – such as the Supreme Court’s verdict last month that the government’s previous version of the Rwanda scheme was unlawful – less likely.

However, Sunak’s third way has led to both the right and left of the party voicing concerns and doubts over whether it will pass at second reading. The last time a government bill was defeated at a similar stage was in 1986 on Sunday trading.

While Sunak has said that this will not be a confidence vote, the stakes are still very high

While Sunak has said that this will not be a confidence vote, the stakes are still very high. There is little appetite for a ‘Plan C’ in No. 10 and little time between now and an election to make another plan work. It means Sunak is betting the house on getting his bill through. The One Nation group met on Monday evening and are expected to back it. But it’s the right where Sunak faces the biggest headache. If 29 Tory MPs vote against it, Sunak faces defeat. Around 40 MPs on the right of the party are planning to rebel. A senior Tory tells me they think it will ‘go right to the wire’.

So, how could today play out?

1. Bill passes at second reading
   The best case scenario for Sunak today is that his charm offensive pays off, the whipping operation works and the Prime Minister wins the vote. At that point, Sunak’s plan remains alive and the battle is put off until the new year. Then, in January when MPs return, a battle looms over potential amendments to the bill. Sunak and his team will spend the holidays talking to potential rebels in a bid to get the bill through the later stages and then the House of Lords. In Sunak’s favour when it comes to this scenario is the fact that, while European Research Group (ERG) chair Mark Francois is very critical, known Sunak critics such as Priti Patel have come out to say they will back the bill.
2. The government pulls the vote
   If the Whips’ Office decide they don’t have the numbers to win the vote, the government could choose to pull the vote. However, this would be an admission of defeat, lead to claims Sunak had lost his nerve and raise doubts that Sunak could ever salvage the bill.
3. The Right unites to sink Sunak’s bill
   The worst case scenario for Sunak is that he cannot appease the right of the party and he faces a mass rebellion of MPs choosing to vote with Labour against the bill. The ERG has given a damning verdict, suggesting that the bill is incomplete and Sunak ought to start again. There is little appetite in No. 10 to do this, not least because of doubts that MPs on the left would back a strengthening of the bill and concern that the Rwandan government will pull the scheme. The ERG will meet again before the vote to discuss which way to go (the mood music from them is that it is a choice between voting against and abstaining). If the ERG team up with the Common Sense Group and the New Conservatives to oppose the bill it could mean a dangerous number of rebels for the government.
4. Sunak loses on abstentions
   One scenario most worrying government aides is that they lose the bill on abstentions. If 57 Tories abstain then the bill won’t pass. ‘There is a danger we abstain our way to defeat,’ says a government adviser. In this scenario, MPs walk back from the brink (in their minds at least) by choosing not to fully oppose the bill but merely abstain. MPs view this as the lesser evil, but if the number doing so is so high that Sunak still loses the vote, it will have the same effect as voting against. This is why some MPs on the right who plan to back the bill will today be telling their colleagues of the potential consequences of losing the vote. As one MP puts it: ‘It’s a domino effect – they are thinking about the first domino if they do this but not where it leads.’ There is a concern that some MPs voting against on policy ground haven’t thought through what it could mean for Sunak more generally.

And if Sunak loses at second reading, what could follow?

1. Sunak becomes the new Theresa May
   The Brexit parallels are coming thick and fast this week. Once again, a Tory leader faces two seemingly irreconcilable tribes fighting over a policy where purity may beat what is politically possible. Were Sunak to lose the vote, he would not have an easy Plan C and many MPs and aides believe he would find his authority shot and in the position Theresa May found herself in during the Brexit years when she was pushed around by her party. ‘It would be Theresa May all over again,’ says a Tory MP.
2. Sunak faces a no confidence vote
   If Sunak loses the vote, several MPs believe no confidence letters could go in. Were this to hit the 15 per cent of the party required, Sunak would face a no confidence vote. The Christmas recess ought to act as a fire break for this happening this year, but it could be a scenario for the new year. Sunak would very likely win the vote, but politically there isn’t really such a thing as a leader triumphing in a confidence vote. As soon as the vote comes, you are in trouble. It would be taken as a sign that Sunak was on borrowed time.
3. Sunak opts for an earlier election than planned
   One of the tricks Sunak still has to play that his party does not is when an election is called. While the idea of a Spring election is disliked by many senior figures, an early 2024 election could start to look like the best choice if the party is beginning to unravel. If Sunak faces pressure from his own side, he could decide to go to the polls to put his Rwanda policy to the public, or go before things got any worse.
4. Sunak’s premiership ends
   If Sunak loses the vote and feels he has nowhere to go with his flagship Rwanda policy, he could decide to give his party a final choice to back him or look elsewhere. In this scenario, the Tory party would risk changing leader once more before going to the polls. It’s an idea former cabinet minister Lord Frost floated only last week, but it is yet to appeal to the majority of the party.